Auxiliary feed mechanism



Dec. 10, 1 929. E. LAXO ET AL 3,739,153

AUXILIARY FEED MECHANI SM Filed Jan. 2, 1925 2 Sheets-Sheet l Dec. 10, 1929@ E. LAXO ET AL AUXILIARY FEED MECHANISM 2 Sheets-Sheet 2 Filed Jan. 2, 1925 ED wxw ac. to, 1929,

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EEQEATEQN 03 NEW YORK AUXILIARY FEED MEG e' This invention relates to an auxiliary feed mechanism for stacked material and more particularly to a feed mechanism'for stacked metal sheets, the principal object of the ina vention being to provide means for pvercoming the dificulties generally experienced in feeding sheet metal from the bottom of a stack due to the excessive weight thereon by the provision of mechanism which operates to to deliver a few sheets at a time from a supply stack onto a working stack in accordance with the rate at which thesheets are used from the latter stack and in such manner that only a relatively small number of sheets will be maintained in the working stack and its weight will be kept below that at which there would be diificulty in feeding the sheets from the bottom thereof.

. Heretofore, in the operation of machines with which the present device is intended to be used and wherein sheet metal is maintained in stacked form, an attendant has been stationed for the purpose of placing a few sheets of material at a time on the workin stack so that the feed will not be interru ted due to excessive weight on the bottom s set and it has been the purpose of the present device to eliminate the services of such an attendant.

In accomplishing this and other objects of the invention, we have provided the improved details of construction, the preferred forms of which are illustrated in the accompanying drawings, whereinigure 1 shows, in side elevation, a part of a machine equipped with an auxiliary feed mechanism in accordance with the present invention. I

Figure 2 is a front elevation of the same.

Figure 3 is a perspective view, particularly illustrating the ratchet feed mechanism.

Figure 4 is a perspective view illustrating an alternative construction.

Figure 5 is a diagrammatic illustration of an electrically controlled feed mechanism.

Figure 6 is a diagrammatic illustration of another electrically controlled feed device.

Referring more in detail to the drawin 1 and 2, respectively, designate upright members forming the front and rear walls of a hopper and 3 designates horizontal bars across the base of the hopper on which a stack 4 of sheet metal plates, or the like, which will hereinafter he termed the working stack, s supported for delivery, a sheet at a time, into the machine. While the feed mechanism, which delivers the sheets from the bot- .it may be drawn downwardly by an suitable means operating in conjunction wit the feed bgrgs such as the suction device, as indicated a Rotatahly mounted in suitable bearings 8 in end members 9 of the machine frame and slightly above the forward edge of the stack 4 1s a feed shaft 10 having knurled rollers 11 fixed at spaced intervals thereon. Fixed to the upper inner surface of the back memher 2 or the hopper are blocks 12 which serve, with the knurled rollers, as the sup orting means for a stack 13 of sheet metal, w ich we have termed the supply stack and from which sheets of material may be fed onto the working stack 4 as is required to maintain a certain number of sheets of material in the latter stack.

The uprights 1 and the blocks 12 are spaced apart at such distances'that when the lower forward edge of the stack 13 is supported on the row of knurled rollers, the op osite ends or edges of the sheets or matena will be supported in engagement with the blocks 12 and will be disposed in an upwardly, in= clined direction, as shown in Figure 1. Then, upon rotation of the shaft 10 and the knurled rollers 11 the sheets of material will be delivered from the lower end of the stack 13 onto the stack 4; the feedin operation being accomplished by reason 0 the lower edges of the sheets catching in the knurls and being carried therewith to the underside lit . the supp].

oil the rollers where they a e released thus permitting the sheets to to horizontal position onto the lower stack.

As a means for automatically controlling the leading oil the sheets from the supply to the working stach, we have provided a :ieed mechanism comprising a ratchet wheel 20 that is fined at one end oi the shalt l and a gear wheel 2]; that is rotatable on the shalt closely adjacent the ratchet. Spring pressed pawls 22 are pivotally fined on the gear wheel in positions to engage with the ratchet so that the latter may he advanced by rotative movement of? the gear. Below the forward ed e oil the stack is a shaft 25 that is provi ed at one end'with a gear wheel 26 that operates in mesh with the gear 21 and also fined on the shaft 25 is a trip lever comprising an n wardly and forwardly curved arm 27 that 18 adapted to engage with the forward edge of the staclr t and an outwardly extending arm '28 provided with an opening 29 through which a reciprocally driven rod 30 operates A spring 32 that is attached to the lever arm 28 and to one of the upri hts 1 of the frame normally retains the trip lever arm 27 in contact with the stack, lhe rod 30 may be driven by any suitable mechanism operating in synchronism with the reciprocatory movement of the feed bars and has a limited upward and downward movement and is provided at its end with a nut 32 that is adapted, on downward move ment of the rod to engage with the arm 29 and to move the lever and shaft 25, to which it is attached, rotatabl provided that the hei ht of the stack 4 as been reduced to such an extent that the trip may be actuated. With the device so constructed, asmany sheets of material as desired regardless of weight may be placed in the hopper to form stack, then, upon operation of the machine t e rod 30 is moved reciprocally and, with each downward movement, nut 31 engages arm 29' oi the trip lever and causes the shaft 25 to be moved. rotatably and this, through gear 26, causes rotative movements of gear 21. which in turn, through pawls 22, efi'ects rotative movement of shaft and knurls 11 which operate to feed the sheets from the bottom of stack 13 onto bars 3 to form the working stack As this latter stack is built up, the arm 27 of the trip device contacting with the forward edge thereof causes a downward shifting of the arm 28 which finall as stack 4 reaches a certain redetermine height or number of sheets 1s shifted clear of the movement of the nut 31 on rod 30 and the feeding action is discontinued.

As the machine continues to operate and the feed arms 5 deliver the sheets from the working stack into the machine, the arm 27 of the trip .lever, under tension of s ring 32, moves inwardly in accordance wit the decrease in height of the stack and this again resales brings arm 28 bacl: to position where it can be actuated by the nut 31 to advance the ratchet wheel to again feed from the supply onto the worldng stack.

lt is th be noted hat the arm 27" is curved inwardly such manner that it will cause the rate oil-leading out sheets to the working stack to be or slow dependent upon the height of the stack, that is, the stack is nearly depleted there will be a delivery of more sheets at a time and as it approaches its maximum height the movement of the arm becomes less and the number of sheets delivered from the supply stack with each reciprocal movement or the rod 30 becomes fewer.

ln Figure at we have shown an alternative construction wherein the shaft 10 has a ratchet feed wheel fixed thereon and a teed lever'dO pivoted on the shaft adjacent the ratchet and pivotally connected at its outer end to the reciprocating rod 30. 0n this lever is adpawl ii that is urged by a spring 42 towar driving engagement with the ratchet. @n the shait is a trip 44 adapted to engage the edge of stack 13 and on the other end is a dog 45 adapted to engage the awl ll to normall retain it disengaged trom the ratchet. hen the stack 4 becomes depleted to such an extent that a laterally extended end M on the trip slips over thestack it allowing the dog to release the pawl into driving contact with the ratchet.

In Figure 5 is another alternative construction wherein the lower sheets of the supply stack are supported by an electro-magnet having circuit wire connections 51 and 52 through which a circuit is normally closed. In this circuit is a control switch comprising a pivoted dog 53 with a contact 54 adapted to engage a contact 55. These contacts are normally held engaged by engagement of the dog with the stack a, but should the latter be depleted, the dog will move to open the circuit and thus release sheets from the supply.

In Figure 6 is still another construction wherein the feed shaft 10 is driven by a worm wheel held frictionally between disks 61-61 that are keyed to the shaft. An electro-magnet 62 is disposed adjacent to a disk 65 on the shaft 10 and when it is energized it magnetically holds the disk against rotation. The magnet in this case is controlled by switch mechanism the same as before described in connection with Figure 5.

With devices of this character itis possible to keep a large supply of blanks, or sheets in the hopper without interfering with the feed for the reason that only a few sheets are released at a time to the working stack.

Having thus-described our invention, what we claim as new therein and desire to secure by Letters-Patent, is:

1. The combination with a supply of stacked sheet material and a working stack its iii

of said material of a feed mechanism comprising a rotatably mounted shaft, a plurallty of knurled rollers on said shaft in supporting engagement with the supply stack and adapted when rotated to effect the delivery of material from the supply onto the working stack, a second oscillatory movable shaft having a driving connection with the first shaft, a trip lever fixed on the second shaft having an arm adapted to engage with the Working stack of material and to move in accordance with the increase or decrease in height of the said stack andhaving a laterally directed arm, a reciprocally driven shaft and a nut on said reciprocally driven shaft adapted at times' to engage with said laterally directed arm to effect rotative movement of the second shaft and a consequent feeding movement of the first shaft.

2; The combination with a supply of stacked sheet material and a working stack of said material, of a feed mechanism comprising a rotatably mounted shaft, a plurality of knurled rollers on said shaft in supporting engagement with said supply stack and adapted when moved rotatably to efi'ect the delivery of material from the supply to the working stack, a ratchet Wheel fixed on said shaft, a gear wheel rotatable on the shaft adjacent the ratchet, pawls on said gear wheel adapted to engage and advance the ratchet wheel, a second oscillatory mounted shaft, a gear on the second shaft in mesh with the first gear, a yieldable trip lever on the second shaft comprising an arm adapted to engage with the working stack and to move in accordance with the decrease or increase in the height thereof and having a laterally directed arm provided with an opening, a reciprocally driven shaft operable through said opening and a nut on said shaft adapted toengage at times with the said arm to effect rotative movement of the second shaft.

3. A device as in claim 2 wherein the first mentioned arm of the trip lever is curved so as to effect a faster rate of feeding of material from the supply to the Working stack when the supply in the working stack is low and a slower feed when it is near its maximum.

Signed at Seattle, King County, Washington, this 22 day of December, 1924.

ED LAXO. NORBERT J. SCHAAL. 

